Cobalt(II,III) oxide

Cobalt(II,III) oxide[1]
IUPAC name

cobalt(II) dicobalt(III) oxide
Other names

cobalt oxide, cobalt(II,III) oxide, cobaltosic oxide, tricobalt tetroxide
Identifiers
CAS number 1308-06-1 Y
ChemSpider 9826389 Y
RTECS number GG2500000
Jmol-3D images Image 1
Properties
Molecular formula Co3O4

CoO.Co2O3
Molar mass 240.80 g mol−1
Appearance black solid
Density 6.11 g/cm3
Melting point

895 °C
Boiling point

900 °C (decomposes)
Solubility in water Insoluble
Solubility soluble in acids and alkalis
Hazards
R-phrases R40 R41 R42 R43
S-phrases S36/37
NFPA 704
0
2
0
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Except where noted otherwise, data are given for materials in their standard state (at 25 °C, 100 kPa)
Infobox references

Cobalt(II,III) oxide is inorganic compound with the formula Co3O4. It is one of two well characterized cobalt oxides. It is a black antiferromagnetic solid. As a mixed valence compound, its formula is sometimes written as CoIICoIII2O4 and sometimes as CoO.Co2O3.[2]

Contents

Structure

Co3O4 adopts the normal spinel structure, with Co2+ ions in tetrahedral interstices and Co3+ ions in the octahedral interstices of the cubic close-packed lattice of oxide anions[2].

tetrahedral coordination geometry of Co(II) distorted octahedral coordination geometry of Co(III) distorted tetrahedral coordination geometry of O

Synthesis

Cobalt(II) oxide, CoO, converts to Co3O4 if heated to around 1000 °C in air. Above 900 °C, CoO is stable.[3] These reaction are described by the following equilibrium:

Co3O4 \overrightarrow{\leftarrow} 3 CoO + 1/2 O2

Research

This inorganic compound is currently utilized in the process of artificial photosynthesis. Artificial photosynthesis is being used to create an alternative liquid fuel.

Safety

Cobalt compounds are potentially poisonous in large amounts.[4]

References

  1. ^ Sigma-Aldrich product page
  2. ^ a b Greenwood, Norman N.; Earnshaw, Alan (1997). Chemistry of the Elements (2nd ed.). Oxford: Butterworth-Heinemann. p. 1118. ISBN 0080379419. 
  3. ^ Handbook of Preparative Inorganic Chemistry, 2nd Ed. Edited by G. Brauer, Academic Press, 1963, NY. p. 1520.
  4. ^ MSDS